TY - JOUR
T1 - Assessing the accuracy and drought utility of long-term satellite-based precipitation estimation products using the triple collocation approach
AU - Bai, Xiaoyan
AU - Wang, Peng
AU - He, Yanhu
AU - Zhang, Zhenxing
AU - Wu, Xiaoqing
N1 - Funding Information:
This research was financially supported by the Natural Science Foundation of Guangdong Province , China (Grant No. 2021A1515010558 ), the National Key R&D Program of China ( 2017YFC0405900 ), the National Natural Science Foundation of China (Grant Nos. 51509040 , 5171101598 , 51979043 and 51709127 ).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/12
Y1 - 2021/12
N2 - Satellite-based precipitation products (SPP) have been the focus of much attention for their potential utility of drought monitoring and analysis. Assessing the accuracy and drought performance of the SPPs for ungauged areas is urgent and also challenging. This study comprehensively investigated the performance of the triple collocation (TC) approach, an assessment approach requiring no benchmark data, the accuracy and drought utility assessment of the SPPs. Furthermore, we applied the TC approach experimentally to the SPPs throughout mainland China. The China monthly Precipitation Analysis Product (CPAP), a gridded gauge-based precipitation dataset, was employed to validate the TC approach. Results demonstrate the effectiveness of the TC approach in retrieving spatial patterns in the accuracy and drought performance (via short-timescale drought indices) of the SPPs, but systematic bias was observed. Moreover, the TC approach exhibits a weak performance in assessing the long-timescale drought indices. By comparing the assessment results, the TC approach reveals the potential underestimation of the SPP accuracy by the traditional assessment approach for some ungauged regions. In general, the proposed TC outperforms the traditional approach in qualitatively assessing the performance pattern of SPPs over ungauged and poorly gauged areas, but the systematic bias of TC needs attention when quantitatively determining SPP performance.
AB - Satellite-based precipitation products (SPP) have been the focus of much attention for their potential utility of drought monitoring and analysis. Assessing the accuracy and drought performance of the SPPs for ungauged areas is urgent and also challenging. This study comprehensively investigated the performance of the triple collocation (TC) approach, an assessment approach requiring no benchmark data, the accuracy and drought utility assessment of the SPPs. Furthermore, we applied the TC approach experimentally to the SPPs throughout mainland China. The China monthly Precipitation Analysis Product (CPAP), a gridded gauge-based precipitation dataset, was employed to validate the TC approach. Results demonstrate the effectiveness of the TC approach in retrieving spatial patterns in the accuracy and drought performance (via short-timescale drought indices) of the SPPs, but systematic bias was observed. Moreover, the TC approach exhibits a weak performance in assessing the long-timescale drought indices. By comparing the assessment results, the TC approach reveals the potential underestimation of the SPP accuracy by the traditional assessment approach for some ungauged regions. In general, the proposed TC outperforms the traditional approach in qualitatively assessing the performance pattern of SPPs over ungauged and poorly gauged areas, but the systematic bias of TC needs attention when quantitatively determining SPP performance.
KW - Accuracy assessment
KW - Drought utility
KW - Mainland China
KW - Satellite-based precipitation product
KW - Standardized Precipitation Index
KW - Triple Collocation approach
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U2 - 10.1016/j.jhydrol.2021.127098
DO - 10.1016/j.jhydrol.2021.127098
M3 - Article
AN - SCOPUS:85118510278
SN - 0022-1694
VL - 603
JO - Journal of Hydrology
JF - Journal of Hydrology
M1 - 127098
ER -